Christopher D. Beaty is a senior fellow in the Division of pulmonary and Critical Care Medicine at the University of Washington. After completing his medical residency and clinical pulmonary training, he entered the laboratory of Dr. Christopher B. Wilson to pursue a research interest in the regulation of lung, inflammation. Dr. Beaty has focused on signal transduction mechanisms as they relate to alveolar macrophage function and is deeply committed to a career in academic medicine. To become a viable independent investigator Dr. Beaty will require an additional 3 years of protected time in the laboratory. Alveolar macrophages (AM) are potent sources of pro-inflammatory cytokines including TNF and EL-8 that are important in the regulation of inflammation. One of the most potent stimuli for the release of TNF and EL-8 from AM is bacterial Upopolysaccharide (LPS). The mechanisms by which LPS induces the production of TNF and IL-8 by alveolar macrophages are not fully defined. The central focus of this proposal is to examine the signal transduction pathways involved in the LPS induced production of TNF and EL-8 by AM. Preliminary data using inhibitors specific for tyrosine kinases and tyrosine phosphatases suggest that these molecules are important in LPS induced TNF production by monocytes. Similar preliminary experiments using inhibitors of selected serine/threonine kinases and pertussis toxin sensitive G proteins have, thus far, failed to demonstrate the importance of these molecules. This proposal examines the hypothesis that phosphorylation of proteins on tyrosine residues is an important event in LPS mediated macrophage signal transduction. This specific aims seek to: 1) establish that tyrosine kinase and tyrosine phosphatase activity is necessary for LPS induced production of TNF and EL-8 by macrophages, including AM; 2) compare the roles of tyrosine kinases/phosphatases to those of the above mentioned serine/ threonine kinases and pertussis toxin sensitive G proteins; 3) evaluate whether the proposed action of the tyrosine kinases/phosphatases on TNF IL-8 production is at the level of transcription, mRNA accumulation/stability and/or translation; and 4) identify the specific tyrosine kinase(s) involved in this process and selective inhibitors of this function. Dr. Wilson's laboratory consists of 3 postdoctoral fellows, 4 technicians and an independently NIH funded investigator, Dr. David Lewis. Regular laboratory meetings, seminars shared with other laboratories, limited advanced coursework, review of progress by an ad hoc committee of experts will facilitate career development. Dr. Beaty feels strongly that Dr. Wilson has provided him with the supportive environment necessary to further develop his research skills.